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  <title>Registers a PHP function for use as an SQL aggregate function</title>

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 <div class="refnamediv">
  <h1 class="refname">SQLite3::createAggregate</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.3.0)</p><p class="refpurpose"><span class="refname">SQLite3::createAggregate</span> &mdash; <span class="dc-title">Registers a PHP function for use as an SQL aggregate function</span></p>

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 <div class="refsect1 description" id="refsect1-sqlite3.createaggregate-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="modifier">public</span> <span class="type">bool</span> <span class="methodname"><strong>SQLite3::createAggregate</strong></span>
    ( <span class="methodparam"><span class="type">string</span> <code class="parameter">$name</code></span>
   , <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$step_callback</code></span>
   , <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$final_callback</code></span>
   [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$argument_count</code><span class="initializer"> = -1</span></span>
  ] )</div>

  <p class="para rdfs-comment">
   Registers a PHP function or user-defined function for use as an SQL
   aggregate function for use within SQL statements.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-sqlite3.createaggregate-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<em><code class="parameter">name</code></em></dt>

     <dd>

      <p class="para">
       Name of the SQL aggregate to be created or redefined.
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">step_callback</code></em></dt>

     <dd>

      <p class="para">
       The name of a PHP function or user-defined function to apply as a
       callback for every item in the aggregate.
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">final_callback</code></em></dt>

     <dd>

      <p class="para">
       The name of a PHP function or user-defined function to apply as a
       callback at the end of the aggregate data.
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">argument_count</code></em></dt>

     <dd>

      <p class="para">
       The number of arguments that the SQL aggregate takes. If
       this parameter is negative, then the SQL aggregate may take
       any number of arguments.
      </p>
     </dd>

    
   </dl>

  </p>

 </div>


 <div class="refsect1 returnvalues" id="refsect1-sqlite3.createaggregate-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   Returns <strong><code>TRUE</code></strong> upon successful creation of the aggregate, <strong><code>FALSE</code></strong> on
   failure.
  </p>
 </div>


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